A novel magneto-optic switch based on nanosecond pulse

With the rapid development of all-optical network, we bring forward more and more requirements to the performance of the optical switches. Therefore, a novel magneto-optic switch based on nanosecond pulse is designed and investigated in this study. It is characterized by no moving parts, high switching speed, and small size etc. The research of magneto-optic switch mainly involves the design of optical route and nanosecond pulse generator. The optical route designment includes the selection of magneto-optic crystal, the route designment and performance analysis of polarized light in the MO switches, as well as the design of magnetic route in Faraday rotator. A bismuth-substituted rare-earth iron garnet single crystal is chosen as magneto-optic material, and a current solenoid is used to generate the applied magnetic field. The design of nanosecond pulse generator is based on the avalanche multiplier effect of avalanche transistor. Many kinds of avalanche transistor are studied in the experiment. The experimental results indicate that the rise time of the output pulse is about 2–5ns, the pulse width is about 6–20ns, while the pulse amplitude is about 30–150V, thereby it is satisfying for the magneto-optic switch used in all-optic network. By controlling the magnetization of the magneto-optic material, the optical beam can be stably switched and the measured switching time is about 100–200ns.